JP2006075364A - Method for evaluating sensory stimulation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for evaluating sensory stimulation by which a difference in the sensory stimulation can be objectively and concretely evaluated. <P>SOLUTION: The electrodes of an electrocardiogram measuring instrument and a galvanic skin response measuring instrument are attached to a subject. When reference stimulation is loaded to the subject, a substance A to be tested is applied onto the left forearm of the subject, then a substance B to be tested is applied onto the right forearm, thereafter ECG (electrocardiogram) and GSR (galvanic skin response) data are obtained from each of the right/left forearms. The transition of a heart rate is calculated from ECG data, and a power spectrum is obtained from the transition for each section of one minute. In the power spectrum, evaluation is carried out using an LF value/HF value being the ratio of the LF value obtained by integrating the sections of frequencies of 0.05 to 0.15 Hz to the HF value obtained by integrating the sections of frequencies of 0.15 to 0.30 Hz. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for evaluating sensory stimulation when using cosmetics such as hair cosmetics, for example.

Conventionally, evaluation of sensory irritation given to users by cosmetics such as hair cosmetics has been performed mainly by sensory statistics evaluation that relies on human senses.
Other evaluation methods include a method of measuring keratin water content, transdermal water transpiration, a method of measuring current perception threshold (CPT), a method of measuring blood IgE, and an evaluation method based on scratching behavior of mice. And a method by measuring the in vitro calcium ion concentration (see Patent Document 1).
Japanese Patent Application No. 2001-180366

  However, human sensory statistics evaluation methods have poor objectivity, and the difference in sensory stimulation cannot be specifically compared numerically. Moreover, it cannot be said that other evaluation methods are sufficient methods.

  This invention is made | formed in view of the above point, and it aims at providing the sensory stimulus evaluation method which can evaluate the difference of a sensory stimulus objectively and concretely.

(1) The invention of claim 1
A sensory stimulus evaluation method for evaluating a sensory stimulus generated by a test substance in a subject, the heartbeat variability of the subject when the test substance is used for the subject, and a size of a low frequency component in a predetermined frequency range Measuring the magnitude of a high frequency component in a higher frequency range than the low frequency component, and evaluating the intensity of the sensory stimulus based on the magnitude of the low frequency component and the magnitude of the high frequency component. The gist of the characteristic sensory stimulus evaluation method is as follows.

  In the sensory stimulus evaluation method of the present invention, the strength of the sensory stimulus is objectively and specifically evaluated by evaluating the strength of the sensory stimulus based on the size of the low frequency component and the size of the high frequency component. Can do.

The low frequency component is a frequency component that reflects the sympathetic nerve tension, and is, for example, a component in the range of 0.05 to 0.15 Hz. The high-frequency component is a component having a frequency that reflects the vagus nerve tension, and is, for example, a component in the range of 0.15 to 0.30 Hz.
(2) The invention of claim 2
The gist of the sensory stimulus evaluation method according to claim 1, wherein the low-frequency component is a component having a frequency in a range of 0.05 to 0.15 Hz.

In the present invention, the low frequency component having a frequency in the range of 0.05 to 0.15 Hz reflects sympathetic nerve tension. Sympathetic tone corresponds to the intensity of discomfort when the test substance is used on the subject. Therefore, according to the present invention, the magnitude of the low-frequency component is measured, and the magnitude of the low-frequency component relative to the magnitude of the high-frequency component is used for evaluation, so that the intensity of sensory stimulation of the test substance can be objectively determined Can be evaluated.
(3) The invention of claim 3
The gist of the sensory stimulus evaluation method according to claim 1, wherein the high-frequency component is a component having a frequency in a range of 0.15 to 0.30 Hz.

  In the present invention, a component having a frequency in the range of 0.15 to 0.30 Hz as a high frequency component reflects the tension of the vagus nerve. In general, the degree of vagus nerve tension is contrary to the degree of sympathetic nerve tension, and therefore the magnitude of the high-frequency component in the present invention is opposite to the sympathetic nerve tension.

Therefore, in the present invention, the magnitude of the high-frequency component is measured, and the magnitude of the low-frequency component relative to the magnitude of the high-frequency component is used for evaluation, thereby objectively and specifically evaluating the strength of sensory stimulation of the test substance. can do.
(4) The invention of claim 4
4. The sensory stimulus evaluation method according to claim 1, wherein strength of the sensory stimulus is evaluated based on a ratio of the magnitude of the low frequency component to the magnitude of the high frequency component. To do.

  In the present invention, the low frequency component is a component reflecting the intensity of discomfort when the test substance is used for the subject, and the magnitude of the high frequency component tends to contradict the magnitude of the low frequency component. Therefore, the ratio of the magnitude of the low frequency component to the magnitude of the high frequency component is a value that increases in accordance with the intensity of the sensory stimulus when the test substance is used for the subject.

Since the present invention performs the evaluation based on the ratio of the size of the low frequency component to the size of the high frequency component, the strength of sensory stimulation when the test substance is used for the subject is objectively and specifically evaluated. be able to.
(5) The invention of claim 5
5. The low-frequency component and the high-frequency component are extracted by performing Fourier transform on the heart rate variability, and the magnitudes of the extracted low-frequency component and the high-frequency component are measured. The gist is a sensory stimulus evaluation method described in the above.

According to the present invention, the magnitude of the low frequency component and the magnitude of the high frequency component can be accurately measured.
(6) The invention of claim 6
A sensory stimulus evaluation method for evaluating a sensory stimulus generated by a test substance in a subject, wherein the strength of the sensory stimulus is evaluated based on a measured value of skin electrical reflex of the subject when the test substance is used for the subject. The gist of the sensory stimulus evaluation method is characterized by this.

  In the present invention, when a test substance is used for a subject, evaluation is performed using the fact that the skin electrical reflex accompanying sweating of the subject changes according to the intensity of sensory stimulation by the test substance. That is, it is evaluated that the sensory stimulus of the test substance is stronger as the measured value of the electrodermal reflection when the test substance is used is higher, and that the sensory stimulus of the test substance is weaker as the measured value of the electrodermal reflection is lower.

According to the present invention, since the intensity of sensory stimulation is evaluated based on the measured value of electrical skin reflex associated with the subject's perspiration, an objective and specific evaluation can be performed.
(7) The invention of claim 7
7. The sensory stimulus evaluation method according to claim 6, wherein one of the electrodes in skin electric reflex measurement is attached to a subject's finger and the other electrode is attached to another finger of the subject to measure the skin electric reflex. To do.

According to the present invention, skin electrical reflection can be accurately measured.
(8) The invention of claim 8
The gist of the sensory stimulus evaluation method according to any one of claims 1 to 7, wherein a measured value when a reference stimulus having a predetermined stimulus intensity is given to a subject is used as an evaluation criterion.

  In the present invention, since a measurement value obtained when a reference stimulus having a predetermined stimulus intensity is given to a subject is used as an evaluation criterion, how much the skin becomes sensitive by application of the test substance (how much the threshold value has changed). Or) can be confirmed.

  Here, as a measurement value when the reference stimulus having a predetermined stimulus intensity is given to the subject, in the inventions of claims 1 to 5, the magnitude of the low frequency component when the reference stimulus is given to the subject. The ratio of the size of the high frequency component and the size of the low frequency component to the size of the high frequency component can be mentioned. In the inventions of claims 6 to 7, the skin accompanying sweating of the subject when the reference stimulus is given to the subject The measured value of electrical reflection is mentioned.

  According to the present invention, even if the skin condition of the subject fluctuates, the intensity of the test substance stimulation is determined by comparing the evaluation value when the test substance is applied with the evaluation value when the reference stimulus is applied. Judgment can be made.

Examples of the reference stimulus include a mechanical stimulus.
(9) The invention of claim 9
The gist of the sensory stimulus evaluation method according to claim 1, wherein the test substance is a cosmetic.

  According to the present invention, the intensity of sensory stimulation of cosmetics such as hair cosmetics can be objectively and specifically evaluated.

  Examples of the embodiments of the present invention (examples) will be described below.

a) The sensory stimulus evaluation method of the present embodiment will be described with reference to FIGS.
(i) An electrocardiogram measuring device was attached to the subject's chest. Moreover, the electrode of the electrodermal reflectance measuring apparatus (GSR measuring apparatus) was attached to the index finger and ring finger of the subject. The subjects were T and S, and the same test was performed.

  (ii) While the subject was at rest, ECG (electrocardiogram) data was acquired using an electrocardiogram measurement apparatus, and GSR data was acquired using a GSR measurement apparatus.

  (iii) A test subject was loaded with a reference stimulus, and ECG and GSR data at that time were acquired. Here, the reference stimulus is a mechanical stimulus having a certain strength to be applied to a portion to which the test substance is applied later.

  (iv) Test substance A was applied to the left forehead of the subject. The application area was 5 cm × 10 cm. Here, the test substance A was a large number of people who answered that stimulation was strong in a panel test of 50 persons.

(v) ECG and GSR data were obtained for 15 minutes after the application of test substance A in (iv).
(vi) Test substance B was applied to the subject's left forehead. The application area was 5 cm × 10 cm. Here, the test substance B is one in which a small number of people answered that stimulation was strong in a panel test of 50 persons.

(vii) ECG and GSR data were obtained for 15 minutes after the application of test substance B in (vi).
FIG. 1 shows ECG and GSR measurement data immediately after application of the test substance A and 5 minutes after application when a reference stimulus is applied. FIG. 1 also shows the transition of heart rate obtained from ECG by the method described later.

(viii) The data obtained in (ii), (iii), (v), and (vii) were analyzed.
First, as shown in FIG. 2, the transition of the heart rate was calculated from the ECG. Specifically, by calculating 60 / x by setting the RR interval in ECG (the interval from the largest R wave that appears in a spike shape in the ECG waveform to the next R wave) to x (sec), The change in heart rate (beats / minute) was determined.

Next, as shown in FIG. 2, a power spectrum was obtained from the change in heart rate. This power spectrum is obtained in each section by dividing the transition of the heart rate into sections of one minute. In order to obtain the power spectrum, first, the autocorrelation coefficient was obtained according to the following formula (1). In Equation (1), foutput (n) is the nth autocorrelation function, ftemplate (k) is the kth data value, and fwaveform (n) is the nth data value. K is a total data table used for calculation.

  Next, fast Fourier transform was performed to obtain a power spectrum as shown in FIG. FIG. 3 shows power spectra at 1 minute, 2 minutes, 3 minutes, 4 minutes, and 5 minutes after application of the test substance A when a reference stimulus is applied. In the derivation of the power spectrum, the trend is subtracted (this draws a line between the endpoints and the slope is subtracted from the waveform), and the average value is subtracted (the average of all points in the selected area is calculated and the waveform is calculated. Subtracted from).

  Next, as shown in FIG. 3, in the power spectrum, a section (low frequency component) with a frequency of 0.05 to 0.15 Hz was integrated, and this value was used as the LF value. Moreover, the section (high frequency component) of the frequency 0.15 to 0.30 Hz was integrated, and this value was defined as the HF value. In addition, since the power spectrum was calculated | required for every 1-minute area in transition of a heart rate as mentioned above, this LF value and HF value are also calculated for every minute.

  Table 1 and FIG. 4 (a) show the LF value, HF value, and LF value / HF value until 5 minutes have passed since the test substance A was applied to the subject T in (iv). Table 1 and FIG. 4A also show the LF value, HF value, and LF value / HF value when mechanical stimulation is applied.

In addition, Table 2 and FIG. 4B show the LF value, HF value, and LF value / HF value until 5 minutes have passed since the test substance B was applied to the subject T in (vi). Table 2 and FIG. 4B also show the LF value, HF value, and LF value / HF value when mechanical stimulation is applied.

  As shown in Table 1 and FIG. 4 (a), the LF value greatly increased and the HF value remained low after 5 minutes from the application of the test substance A, so the LF / HF value increased greatly. It is larger than the LF / HF value at the time of reference stimulus loading. On the other hand, as shown in Table 2 and FIG. 4B, even when 5 minutes have elapsed since the application of the test substance B, the HF value and the LF value do not change greatly, and the LF / HF value does not change significantly. And the value of LF / HF value at the time of 5 minutes has become smaller than the LF / HF value at the time of a reference stimulus load.

Similarly, for subject S, the LF value, HF value, and LF value / HF value until 6 minutes have passed after applying test substance A are shown in Table 3 and FIG. Table 4 and FIG. 5B show the LF value, HF value, and LF value / HF value until 7 minutes have passed after application. Tables 3 to 4 and FIG. 5 also show the LF value, HF value, and LF value / HF value when mechanical stimulation is applied.

As shown in Table 3 and FIG. 5 (a), after 5 minutes from the application of the test substance A, the LF value increased greatly and the HF value remained low, so the LF / HF value increased greatly. It is larger than the LF / HF value at the time of reference stimulus loading. On the other hand, as shown in Table 4 and FIG. 5B, even when 5 minutes have elapsed since the application of the test substance B, the HF value and the LF value do not change greatly, and the LF / HF value does not change significantly. And the value of LF / HF value at the time of 5 minutes has become smaller than the LF / HF value at the time of a reference stimulus load.

  Next, the GSR data was divided into 1-minute intervals, and integration was performed in each interval. And the integral value in each area was made into the GSR value. Table 5 and FIG. 6 (a) show GSR values until 15 minutes have passed since the test substance A was applied to the subject T. Table 5 and FIG. 6 (a) also show GSR values from when the test substance B is applied to the subject T until 15 minutes have passed.

Similarly, the GSR values until 9 minutes have passed since the test substance A was applied to the subject S and the GSR values until 9 minutes have passed since the test substance B was applied are shown in Table 6 and FIG. Shown in b).

As shown in Tables 5 to 6 and FIG. 6, in both the subjects T and S, the GSR value greatly increased when the test substance A was applied, but the GSR value when the test substance B was applied was small. There was little change.

As a result of the sensory evaluation, the test subject T replied that the test substance A was more stimulated, and the test subject S replied that both the test substance A and the test substance B were strong, but no difference was felt.
b) Next, the effect which the sensory stimulus evaluation method of a present Example show | plays is demonstrated.

  (i) According to the sensory stimulus evaluation method of this example, FIG. 4 (a) which is a result when the test substance A is applied to the subject T and FIG. 4 (a) which is a result when the test substance B is applied. As is clear from the comparison with b), test substance A with a large number of respondents who responded that stimulation was strong in 50 panelists tested had a high LF / HF value, and test substance B with a small number of respondents said that stimulation was strong. Then, the LF / HF value is low.

  Further, as apparent from the comparison between FIG. 5A, which is the result when the test substance A is applied to the subject S, and FIG. 5B, which is the result when the test substance B is applied, the stimulus is present. The test substance A having a large number of respondents has a high LF / HF value, and the test substance B having a small number of respondents having a strong stimulus in the paneler test has a low LF / HF value.

  Therefore, according to the sensory stimulus evaluation method of the present embodiment, an evaluation corresponding to the number of people who feel that there is a stimulus can be performed based on the LF / HF value. That is, it can be determined that a test substance having a high LF / HF value has a large number of people who feel that there is a stimulus, and a test substance having a low LF / HF value can be determined to have a small number of people who feel that there is a stimulus.

  Moreover, in the sensory stimulus evaluation method of the present embodiment, the evaluation result can be expressed by LF / HF values, so that the difference in sensory stimulus can be objectively and specifically evaluated. This makes it possible to set stimulation criteria at the time of product development with specific numerical values, to verify the effect of reducing stimulation, and to predict the number of people who feel that there is stimulation. Therefore, a product with higher safety can be provided.

  (ii) According to the sensory stimulus evaluation method of this example, the GSR value when the test substance A having a large number of people who answered that the stimulus was strong in the panel test of 50 persons was applied to the subjects T and S. It is clearly higher than the GSR value when the test substance B is applied with a small number of people who answered that it is strong.

  Therefore, according to the sensory stimulus evaluation method of the present embodiment, an evaluation corresponding to the number of people who feel that there is a stimulus can be performed based on the GSR value. Moreover, in the sensory stimulus evaluation method of the present embodiment, the evaluation result can be expressed by the GSR value, so that the difference in the sensory stimulus can be objectively and specifically evaluated.

  This makes it possible to set stimulation criteria at the time of product development with specific numerical values, to verify the effect of reducing stimulation, and to predict the number of people who feel that there is stimulation. Therefore, a product with higher safety can be provided.

  (iii) In the sensory stimulus evaluation method of this embodiment, an evaluation value (LF / HF value or GSR value) when a reference stimulus is given to the subject is obtained. Therefore, it can be confirmed how much the skin has become sensitive to the application of the test substance (how much the threshold has changed).

  Even if the skin condition of the subject fluctuates, it is possible to determine the strength of the test substance stimulus by comparing the evaluation value when the test substance is applied with the evaluation value when the reference stimulus is applied. it can.

  Needless to say, the present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the scope of the present invention.

It is explanatory drawing showing the measurement data in the sensory stimulus evaluation method of an Example. It is explanatory drawing showing the data processing method in the sensory stimulus evaluation method of an Example. It is explanatory drawing showing the data processing method in the sensory stimulus evaluation method of an Example. It is explanatory drawing showing the measurement result in the sensory stimulus evaluation method of an Example. It is explanatory drawing showing the measurement result in the sensory stimulus evaluation method of an Example. It is explanatory drawing showing the measurement result in the sensory stimulus evaluation method of an Example.

Claims (9)

A sensory stimulus evaluation method for evaluating a sensory stimulus generated by a test substance in a subject,
From the heart rate variability of the subject when the test substance is used for the subject, the magnitude of a low frequency component in a predetermined frequency range and the magnitude of a high frequency component in a frequency range higher than the low frequency component are measured. A sensory stimulus evaluation method characterized by evaluating the intensity of the sensory stimulus based on the magnitude of the low frequency component and the magnitude of the high frequency component.   The sensory stimulus evaluation method according to claim 1, wherein the low frequency component is a component having a frequency in a range of 0.05 to 0.15 Hz.   The sensory stimulus evaluation method according to claim 1, wherein the high frequency component is a component having a frequency in a range of 0.15 to 0.30 Hz.   The sensory stimulus evaluation method according to claim 1, wherein the intensity of the sensory stimulus is evaluated based on a ratio of the magnitude of the low frequency component to the magnitude of the high frequency component.   5. The low-frequency component and the high-frequency component are extracted by performing Fourier transform on the heart rate variability, and the magnitudes of the extracted low-frequency component and the high-frequency component are measured. Sensory stimulus evaluation method according to crab. A sensory stimulus evaluation method for evaluating a sensory stimulus generated by a test substance in a subject,
A sensory stimulus evaluation method, wherein the intensity of the sensory stimulus is evaluated based on a measured value of electrical reflex of the subject when the test substance is used for the subject.   7. The sensory stimulation evaluation method according to claim 6, wherein the skin electrical reflex is measured by attaching one electrode to the subject's finger and the other electrode to the subject's other finger in the electrodermal reflection measurement.   8. The sensory stimulus evaluation method according to claim 1, wherein a measurement value obtained when a reference stimulus having a predetermined stimulus intensity is given to the subject is used as an evaluation reference.   The sensory stimulus evaluation method according to claim 1, wherein the test substance is a cosmetic.